docs: def FixedOffset(offset, _tzinfos = {}):
      """return a fixed-offset timezone based off a number of minutes.
  
          >>> one = FixedOffset(-330)
          >>> one
          pytz.FixedOffset(-330)
          >>> one.utcoffset(datetime.datetime.now())
          datetime.timedelta(-1, 66600)
          >>> one.dst(datetime.datetime.now())
          datetime.timedelta(0)
  
          >>> two = FixedOffset(1380)
          >>> two
          pytz.FixedOffset(1380)
          >>> two.utcoffset(datetime.datetime.now())
          datetime.timedelta(0, 82800)
          >>> two.dst(datetime.datetime.now())
          datetime.timedelta(0)
  
      The datetime.timedelta must be between the range of -1 and 1 day,
      non-inclusive.
  
          >>> FixedOffset(1440)
          Traceback (most recent call last):
          ...
          ValueError: ('absolute offset is too large', 1440)
  
          >>> FixedOffset(-1440)
          Traceback (most recent call last):
          ...
          ValueError: ('absolute offset is too large', -1440)
  
      An offset of 0 is special-cased to return UTC.
  
          >>> FixedOffset(0) is UTC
          True
  
      There should always be only one instance of a FixedOffset per timedelta.
      This should be true for multiple creation calls.
  
          >>> FixedOffset(-330) is one
          True
          >>> FixedOffset(1380) is two
          True
  
      It should also be true for pickling.
  
          >>> import pickle
          >>> pickle.loads(pickle.dumps(one)) is one
          True
          >>> pickle.loads(pickle.dumps(two)) is two
          True
      """
      if offset == 0:
          return UTC
  
      info = _tzinfos.get(offset)
      if info is None:
          # We haven't seen this one before. we need to save it.
  
          # Use setdefault to avoid a race condition and make sure we have
          # only one
          info = _tzinfos.setdefault(offset, _FixedOffset(offset))
  
      return info